This post is all about converting your device address in Network to STATIC & establish PORT FORWARDING.

For IOT projects it is easy to test in local setup using the LAN IP starting with 192.x.x.x .But from outside world this IP cannot be reached.Here I will walk you through the steps to contact the local IP from outside world.This procedure is a major step needed in IOT projects , without which external control is not possible.

Following is the setup of my Network. A ROUTER is on the top of the network for which the Internet Service Provider is Airtel . The Router is WIFI enabled so that I can connect multiple devices wirelessly.

Total 3 devices are connected to the Router as shown below.

On switching on the power , the Router (DHCP enabled) assigns local IP addresses to all the devices connected.The IP address assigned is DYNAMIC which means , it changes every time I switch on the Router.

There are two types of IP addresses: STATIC & DYNAMIC

STATIC addresses are just that – unchanging

Dynamic IP addresses are assigned on-the-fly & keeps on changing by every reboot.

Because most home users tend to turn their computers off, even broadband connections, such as DSL and cable, continue to use dynamic addresses. If your computer is off, you don’t need an IP address so someone else might get to use it.

Each time you connect to the internet, your ISP assigns you an IP address to use. This IP address is the Public IP which others use to communicate to your PC.This IP address is DYNAMIC which changes every time you newly connect to web.

The next time you connect, you might get a different address. If you’re only connecting out to the internet, that’s all you need.

If you expect people to connect in, say you want to run a web server that you want people to be able to find and visit, you’ll most likely need a STATIC IP address. A static IP is assigned by your ISP at an extra cost which is unnecessary for a home network.

In this post I shall explain the ways of changing the LOCAL IP address as well as the PUBLIC IP address to STATTIC.Suppose you run a web server on your ESP or Raspberry PI & wish to connect from external world.It will work only for the first time , as you use Dynamic IP to communicate.

Next time you power up , the IP address might have changed.So using a STATIC IP is a must .

Here you can see the Default Gateway is 192.168.1.1 which is the IP of the Router .To port forward settings we need to use this IP on a browser to enter the settings , which we will see later in the post.

Local IP assigned to the PC is the IPV4 address 192.168.1.10

Let us change this to STATIC now.

Open the CONTROL PANEL –> NETWORK and Internet –> Network and Sharing center

Click on “Change adapter settings”

Right Click on the Network connection & select Properties

Select the Internet Protocol Version 4 & double click on it.

Now you see the following screen where selection is done by default to obtain IP automatically.

Change this selection o “USE the following IP address “ & enter the IP as 192.168.1.150

The first three bytes must match that of the default gateway address which is 192.168.1.1

The last byte can be assigned at your will , within the IP range allowed by the router.

Here I change the IP to 192.168.1.150. Note that only the last byte I’ve changed.

Subnet mask & Default gateway are entered as seen in the ipconfig /all window above.

DNS server address also changed as seen in the screen shot below

Reboot your PC to see the changes effective.

Now the IP address of my PC will be 192.168.1.150 & remains STATIC even after reboot.

Regarding the IP of ESP8266 we need not change anything.Once the STATION IP is assigned to ESP8266 , the module remembers the Access Point it has connected & the STA IP assigned .

or issue the command

AT+CIPSTA=”192.168.1.5”

The ESP module remembers the Access Point it has joined with & the IP till you quit the AP.

But on Reset it seems to get changed.

The only way to assign STATIC IP to ESP module is through the Router settings.

In your browser type in the IP address of your Gateway , here it is 192.168.1.1

Under LAN setup look out for DHCP settings.

In latest Routers you see a setting called DHCP RESERVATIONS.

In the IP Address field, type the IP address to assign to the computer or server.
Choose an IP address from the router’s LAN subnet, such as 192.168.1.x.

Type the MAC address of the ESP MODULE server.As the ESP has already joined the AP, it is already on your network, you can copy its MAC address from the Attached Devices screen and paste it here.

Here I will show an example of setting the Static IP in DHCP Reservation under BEETEL Router

In almost all the Routers the settings are the same.Just look out for the wordings HCP RESERVATION” or “DHCP STATIC “ under the LAN setup.

Under DHCP STATIC tab , enter the IP address you want to fix for the ESP module

Feed in the MAC ADDRESS of the ESP device.

You can learn the MAC address from the AT command AT+CIFSR of ESP module.

The MAC address to be entered without any special character like colon.Please check out your Router settings for entering the MAC address (generally given near the MAC address box , how to feed in the address).

Click on ADD to save the settings

Now RESET or power back the ESP module.

The IP address will be the same for ever.The Router will always assign the IP you’ve set for the ESP module.

In a D-Link router, it is under the setup.Go to Setup / Network settings / DHCP reservation. You can then ask the router to give a given MAC address a fixed IP address.
Alternatively, the ESP can request a certain IP address from the router which we’ve seen in the example of Beetel Router above.

Now that the STATIC IP is assigned, let us see the methods of PORT FORWARDING & converting your public IP to STATIC using NO-IP account in PART 2.

In the previous post part-1 I explained the initial setup of starting a Server on PC on a port , setting the Windows firewall to allow the port for external communication , PORT FORWARDING set up in the Router config, etc..

Following screen shot shows the PUTTY terminal which I’ve opened on a different PC with a different IP.

On clicking OPEN button , the ESP Terminal at the other end will respond with

0,CONNECT

This means a connection established on channel 0.

Now type in some characters on the distant PC terminal.

The ESP terminal responds with

+IPD,0,21:characters received

which indicates , it has received 21 characters on channel 0.

The screen shots with HUAWEI symbol (IP 117.252.205.55 ) is that of TERMINAL where ESP module is connected & the screen shot of distant PC is shown with the IP address 180.215.121.135

To send characters from ESP , use the AT command :

AT+CIPSEND=0,15

This indicates that you want to send 15 characters on channel 0.

The ESP will respond with a > symbol & waits till you type 15 characters.

The distant PC now receives the 15 characters you typed inside ESP terminal.

Hence a two communication is established with ESP Terminal & a PC from anywhere in the world.This opens the door for INTERNET OF THINGS where you can control the devices connected to ESP from anywhere in the World.

In the previous post we’ve seen the ways to control the ESP8266 WIFI module from anywhere in the world.The key to success depends on the PORT FORWARDING , where we route the contact on particular port to the local IP address of the WIFI module.

Nowadays USB dongles are used widely for internet access .This post will help you troubleshoot PORT FORWARDING.

Following is the SETUP diagram .

TPLINK ROUTER is on the top of the NETWORK. An MTS USB dongle is plugged to TPLINK Router (model TL-MR 3420 with 3G/4G support).

A Laptop is connected to TPLINK Router on Ethernet using RJ45 cable.

A USB to TTL board is connected to PC on which the ESP 8266 module is wired.

The ESP module is linked to TPLINK Router on WIFI using the AT Command AT+CWJAP=”SSID”,”password”

On switching ON the ROUTER , it assigns LOCAL IP address to the modules connected to it either on RJ45 (wired) or on WIFI.

In our set up the LAPTOP which is connected by wire is assigned 192.168.0.100

& the ESP module which is connected on WIFI is assigned 192.168.0.101.

Note that the allotment of address is on first come basis.When you power off & on the Router again , this allotment may vary.

You can RESERVE the address by selecting the DHCP tab of TPLINK configuration.Here select

Address Reservation & then feed in the MAC address of the devices you’ve connected to the Router.

These are reserved by IANA for private Intranets & NOT ROUTABLE TO INTERNET.

Private addresses are not reachable on the Internet. Therefore, Internet traffic from a host that has a private address must either send its requests to an Application layer gateway (such as a proxy server), which has a valid public address, or have its private address translated into a valid public address by a network address translator (NAT) before it is sent on the Internet.

In my case , the MTS ISP provider hide the PUBLIC IP address.

The MTS dongle does not support VIRTUAL SERVER settings , which means PORT FORWARDING IS NOT POSSIBLE with MTS.

What I couldn’t understand was , while writing my previous blog ,it worked sometimes.While MTS customer support was contacted repeatedly , they finally accepted that port forwarding is blocked by them.

After sleepless nights I’ve found a solution….. Read on my next post ….

In the previous posts we’ve tested the WIFI module in TCP Server/Client mode & how to control from an Android mobile.These are related to LAN – Local Area Network where the WIFI module & Mobile are connected to the same ACCESS POINT (AP).

The AP I’ve used is a WIFI Dongle MTS MBLAZE. For the outside world to contact the ESP module connected to MTS , PORT FORWARDING should be done. This is a method by which the IP address of ESP module is forwarded , so that any one accessing the particular port of external IP will land on the ESP module.

The problem is WIFI Dongles do not allow Port Forwarding . As I’ve previous experience in CCTV DVR port forwarding (you can watch my video on DVR port forwarding Here ) using land line Internet connection , I decided to apply the same technique for ESP WIFI.

Select Protocol as TCP & enter the port number 333 under Specific Local Ports.

Select “Allow the Connection “.

Apply rule to all Domain,Private & Public.

You can name the rule & click Finish to save it.

STEP 5 :Know your External IP & Port Open Condition

The Router is accessed from outside world by its external IP. This external IP is assigned by the ISP provider.Generally this IP is DYNAMIC ,which means every time you switch on your Router , a different IP is assigned.